A Cup of Corrosion

Coffee’s biggest enemy

by Arthur Karuletwa, director of traceability

In 2008, according to the Economist, it wiped out around 40 percent of Colombia’s coffee crop. The Colombian Coffee Growers Federation has since replanted more than three billion coffee trees, with mixed success. To this day, it continues to ravage crops throughout Central America.

The enemy at hand is coffee rust, a fungus that attacks the leaves of coffee trees and causes them to fall off. Initially it appears as small, pale yellow spots, which grow larger and darker in color, eventually taking on the burnished red color that gives the disease its name.

Ideal conditions for growing coffee exist only in the coffee belt, roughly between the Tropics of Cancer and Capricorn.

Without leaves to capture the sun’s energy via photosynthesis, the coffee cherries are deprived of necessary nutrients and stop growing. This leads to smaller yields, which can have disastrous effects on farmers. Even small dips in production can force farmers to turn to other crops — or abandon their land altogether.

Coffee Rust causes leaves to die and fall off, inhibiting photosynthesis.

This fungus, also known as Hemileia vastatrix or “la roya,” was first documented in the 1860s. It’s since spread to every major coffee-producing region in the world, appearing in the Western Hemisphere as recently as 1976.

Fungicides have helped contain coffee rust, but because the spores are dispersed by the wind, long-term eradication has been unsuccessful. Some trees can be saved once infected, but this requires large amounts of chemicals and additives that ultimately damage the soil and, in the end, the coffee.

Coffee Rust affects a farm in Colombia.

The fight is still ongoing. Starbucks is testing and cultivating nearly 200 different rust­-resistant varieties of coffee trees at our experimental nursery at Hacienda Alsacia in Costa Rica. We’re also providing assistance to farmers affected by coffee rust through our new Starbuck One Tree for Every Bag* commitment. For every bag of Starbucks coffee sold at participating stores, we’re donating one new coffee tree.

Young coffee trees ready to be planted.

The future of coffee production in Central America is at stake. Coffee rust impacts not only farmers and their families, but also companies like ours. Together we’ll keep working to make a difference.

For more on our One Tree for Every Bag commitment, click here.
For more stories about coffee, visit our new blog

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